It is known that satellites include two subsystems: the platform and the payload. The platform supports the payload. Typically the payload is designed with a specific mission in mind. A communication payload typically includes a number of transponders that receives the uplink signal and transmits the downlink signal. Consequently, the transponder's receive frequency, bandwidth and transmit frequency are all fixed during the satellite design phase, typically several years before entering into service. The payload is then ‘frozen’ in its design at the contract stage unless a change is particularly foreseen.
During the lifetime of a satellite, however, evolving business and political landscapes, the emergence of new technologies and applications, or even a change of orbital location or owner, can alter the operational requirements on the payload. With the expected lifetime of current commercial satellites exceeding 15 years, the ability to adapt to these changing needs would be highly advantageous. In today's environment, flexibility at the payload level is becoming a more attractive solution. As technology advances, solutions are becoming evident which are more cost effective. This is particularly the case for solutions that must combat the increasing threat of interference. Since operators do not have prior knowledge of where, when or at what frequency interference could be observed, a flexible payload solution is desired to minimize the impact of interference on operation.
There is a variety of approaches that provide in orbit flexibility and that can combat the impact of interference on satellite systems: for example, the payload can comprise adjustable hardware, such as steerable antenna, active antennas which can reconfigure their coverage or hardware enabling to modify the frequency response to combat the interfered signal.
However, the known solutions require significant amount of extra hardware to enable systems to be switched in the event of interference. Given that space is limited on satellites, this can often restrict the overall mission.
Another approach to combat interference is to design an area within which interference could be anticipated and therefore rejected. This region could be potentially very large since we have no prior knowledge of the event. This can significantly over-constrain the design and potentially impact performance. This prudent approach of designing to an enveloping scenario is often taken when in actuality the interference will occur from a small zone within this region.
Besides, interference solutions provided in the prior art focus on rejecting the interference signal such that the effected channels are typically suppressed.